During the manufacture process of a liquid crystal (LC) panel, it needs to form alignment films on both of an array substrate and a color filter substrate for pre-alignment of LC. The process of forming an alignment film usually comprises: firstly applying a polyimide (PI) liquid onto a substrate uniformly to form a PI layer, and then rubbing the PI layer by a roller so as to form an alignment angle or alignment channel in the PI layer as required.
This rubbing process may produce a lot of debris which are different in their dimensions, such as those falling from the PI layer. Conventional debris-removing processes mainly emphasize on the cleaning of the array substrate and the color filter substrate, although it belongs to a mature technology, it easily involves following problems.
First, it's difficult to thoroughly remove the relatively tiny debris in terms of the conventional cleaning manners, thus the working efficiency is low.
Secondly, if the cleaning is not performed thoroughly, the assembled display panel will involve display failure.
Thirdly, the implementation is complicated and also expensive.